When baker's dough is mixed, it is usually blended in a large mixer, and the batch of dough in the mixer must be transferred to a stuffing pump which forms the dough in a continuous stream and moves the dough through subsequent processing equipment such as a metering pump, and through a dough distribution manifold where the single stream of dough is divided into several streams of equal density, and then each stream is moved to a dough divider where each stream of dough is subdivided into dough balls, which after baking, become buns, etc.
The dividing process usually is carefully performed so that each biscuit, bun, etc. divided from the mass of dough is of consistent weight so that when the product is subsequently baked or otherwise cooked, packaged and delivered, each of the products will be of substantially uniform size, weight and density. Examples of equipment used to perform these functions are found in U.S. Pat. Nos. 4,332,538 and 4,449,908.
When dough has been mixed and is waiting to be divided into smaller biscuits, buns, etc., the dough tends to rise so that it becomes less dense and occupies a larger volume per unit of weight. Therefore, while the dough may be at optimum density when still in the mixer, a batch of dough that has been transported to the hopper of a stuffing pump tends to rise, and the batch of dough that is waiting to be handled by the stuffing pump and subsequent processing equipment is likely to be less dense than the first portion of the batch of dough that was processed. Since the equipment used for dividing dough functions to divide the dough into uniform volumes, the dividing equipment continues to form the dough balls with the same volume but with less weight of dough as the dough from the batch rises, causing the subsequent products to be different from those products made from the first dough taken from the batch. As this happens, the dough divider operator usually attempts to compensate for the less dense dough by adjusting the pump pressure, the divider volumetric measuring operation, etc., in an effort to cause the dough balls to be formed in larger volumes but of the same weight.
Attempts have been made to draw the gases from dough as the dough is moved by its stuffing pump toward the dough divider so as to return the dough to its desired mixer density. For example, U.S. Pat. No. 4,449,908 teaches the process of drawing a zone of reduced gas pressure about the dual auger screws of a stuffing pump, which tends to draw the dough into the stuffing pump and to expel gases from the dough which have been released because of the shearing and stretching of the dough. However, the stuffing pump uses interference fit augers with special shaped concave conveying surfaces in order to impart the high pressures to the dough that are necessary to achieve the high pressure and uniform dough product. Further, the shapes of the dual augers and auger housing limits the amount of negative gas pressure that can be applied to the system. If excess negative pressure is used, the dough tends to enter the gas exhaust system. Further, the gas exhaust system usually cannot be started upon start up of the augers, requiring a time delay to start the gas exhaust system.
Thus, it can be seen that it would be desirable to provide a baker's dough stuffing pump which is simple to operate, is of inexpensive construction, and which handles the dough with a minimum of shearing and stretching and disruption of the gluten structure of the dough and which returns the dough substantially to and maintains the dough at mixer density.